Ever wished you could tap into your tot’s seemingly boundless energy? If designers Hyun Joo Lee and Eu Tteum Lee’s concept jump-rope-flashlight comes to life, you could be looking at your new sustainable power source.

Their Jumping Light jump rope, which features an LED flashlight built into one of its handles, converts energy from skipping into electricity. It’s a little silly, to be sure — how many people, kids, included, will actually work out just to get some illumination? But the designers’ tagline has us sold: “Joyful jumping that makes your body and the nature happy.” Who can argue with that?